Fresh corn
Tomatoes
Salt
Pepper
Sugar
Butter

Take equal quantities of green corn cut from the cob, and tomatoes sliced and peeled. Stew together half an hour; season with pepper, salt, and a very little sugar. Stew fifteen minutes longer, and stir in a great lump of butter. Five minutes later, pour out and serve.

Common Sense in the Household by Marion Harland, New York, 1871:

Comment: Do not be confused by the term “green corn.” This recipe dates to the time when corn was simply corn, before different varieties were bred of which some were fed to animals and others known as “sweet corn” were intended for human tables. When corn was just fully ripened, fresh and juicy, it was used in recipes like this. That which was left on the stalk past this point began to dry out and could be either taken to the mill for grinding into corn meal or preserved in the form of hominy. When fully dried it was then considered winter food for either people or livestock.

This is something of an oddity in that we know of no recipes today that are simply corn and tomatoes cooked together. Corn and lima beans, yes; this we know as succotash. Tomatoes and, well, nearly everything else, sure. Corn and tomatoes? Not so much. While these recipes are found in books intended for civilian life, we have no doubt that something very much like this would have been eaten by troops in the field who passed through an area at the right time of year for vegetables to be ripe or close to it. Farmers did not like to see armies of either side passing anywhere nearby for precisely this reason.